Preoperative Knee Society Score Research Articles

Functional outcomes of total knee arthroplasty in patients with Parkinson's disease: A case control study

BackgroundParkinson's disease is a neurodegenerative condition causing coordination loss in musculoskeletal system. Many studies suggest that total knee arthroplasty in patients with Parkinson's disease has unfavorable treatment results and high complication rates. Our hypothesis was that total knee arthroplasty might be an effective procedure in patients with Parkinson's disease. MethodsParkinson's disease patients who underwent total knee arthroplasty between 2006 and 2018 were retrospectively evaluated. Patients who had Parkinson's disease diagnosis before surgery and who had a minimum follow-up duration of 12 months were included. Secondary knee osteoarthritis patients were excluded. A matched control group was randomly formed. Outcome measures were evaluated by preoperative and postoperative Knee Society Score and joint range of motion values. Comparison was made by means of increase in Knee Society Score and range of motion values. Study group patients were reviewed according to Columbia Classification System to determine disease severity. Stages I-II were accepted as “low-grade” and III-IV-V as “high-grade” disease. Another comparison was made between “low-grade” and “high-grade” patients. Patient who showed disease progression after surgery were also compared to patients without progression. ResultsThere were 13 patients in both groups. In study group, mean preoperative and postoperative Knee Society Score values were 45.4 (±16.8) and 85.6 (±7.60); range of motion values were 93.9° (±17.0°) and 99.5° (±9.37°) respectively with a mean follow-up of 64.5 (±44.7) months. In control group, mean preoperative and postoperative Knee Society Score values were 38.8 (±11.5) and 86.1 (±10.0); range of motion values were 100.4° (±14.6°) and 109.2° (±10.2°) respectively with a mean follow-up of 51.8 (±13.6) months. No significant difference was observed between 2 groups (p > 0.05). Mean preoperative KSS and ROM values were significantly lower in high-grade patients (30.0 (±17.0) and 78.8° (±11.8°) respectively) compared to low-grade patients (52.2 (±11.9) and 100.6° (±14.7°) respectively) (p < 0.05). However, mean increase in KSS and ROM values were significantly higher for high-grade patients (p < 0.05). Mean increase in Knee Society Score and range of motion was 32.4 (±10.9) and 1.00° (±9.46°) respectively in patients with progression, 45.4 (±16.8) and 8.63° (±8.00°) in patients without progression (p > 0.05). ConclusionTotal knee arthroplasty is a successful treatment of knee osteoarthritis in Parkionson's disease patients with similar outcomes compared to general population despite disease severity and progression.

The Combination of Inlay Patellofemoral Arthroplasty and Medial Unicompartmental Knee Arthroplasty Versus Total Knee Arthroplasty for Mediopatellofemoral Osteoarthritis: A Comparison of Mid-Term Outcomes

BackgroundTo the best of our knowledge, there have been no studies in the literature related to the use of second-generation inlay patellofemoral arthroplasty and unicompartmental knee arthroplasty combination (inlay PFA/UKA) in the treatment of mediopatellofemoral osteoarthritis (MPFOA). The aim of this study is to evaluate the efficacy of inlay PFA/UKA in MPFOA. MethodsThe study included 49 patients applied with inlay PFA/UKA because of MPFOA and 49 patients applied with TKA, matched one-to-one according to age, gender, body mass index, follow-up period, preoperative Knee Society Score, and range of motion. All the patients were evaluated clinically using the Knee Society Score, Knee Injury Osteoarthritis Outcome Score, and range of motion, and were also evaluated radiologically. Complication rates and length of hospital stay were compared. ResultsThe mean follow-up period was 54 ± 4 and 54.4 ± 3.9 months in inlay PFA/UKA and TKA groups, respectively. (P = .841). No statistically significant difference was determined between the 2 groups in respect of the mean clinical scores at the final follow-up examination (P ≥ .129). Total complications were fewer and length of hospital stay was shorter in the inlay PFA/UKA group than in the TKA group (P = .037 and P = .002). There was no radiographic evidence of progression of lateral compartment osteoarthritis according to Kellgren-Lawrence in any patient in the inlay PFA/UKA group. ConclusionIn selected patient groups, inlay PFA/UKA is an alternative to TKA, with lower complication rates, shorter length of hospital stay, and clinical and functional results similar to those of TKA without osteoarthritis progression in the unresurfaced lateral compartment in the mid-term. Level of EvidenceIII.

Mid-term results of impaction bone grafting in tibial bone defects in complex primary knee arthroplasty for severe varus deformity.

Introduction: Bone defects are a challenging problem encountered occasionally during primary knee arthroplasty. These defects should be meticulously addressed so as to avoid malalignment and premature loosening and failure. Out of the many options available to deal with these defects, impaction bone grafting provides a more biological solution, which is especially important in case of primary knees.Materials and methods: A retrospective analysis was done and patients with severe varus deformity of more than 20 degrees who had undergone primary knee arthroplasty with impaction bone grafting of the tibial condyle defect were followed up.Results: Between 2008 and 2014, out of the 1124 patients who underwent primary total knee arthroplasty, only 26 knees in 23 patients met the inclusion criteria. The amount of varus deformity ranged from 20 to 35 degrees. Follow-up ranged from 3 to 8 years with an average of 6 years. The average pre-operative Knee Society Score (KSS) and Western Ontario McMaster Universities (WOMAC) score were 24.2 and 78, respectively. There were significant improvements in the post-op scores, with the average KSS being 90.2 and the WOMAC being 38.Conclusion: Impaction bone grafting provides an invaluable option to the orthopedic surgeon for managing bone defects, especially in case of primary knee arthroplasty as it reconstitutes the bone stock.

Revision for Aseptic Loosening of Primary Total Knee Arthroplasty

Background: the modes of failure of total knee replacement(TKR) can be classified as intra-articular or extraarticular, as biological or mechanical, as early or late. Aseptic loosening is one of leading cause of failure of total knee replacement. Purpose: it was to spot light on different surgical strategies; to assess the results of 20 cases of revision total knee arthroplasty after aseptic loosening of primary total knee arthroplasty. Materials and Methods: this is a prospective interventional study which was conducted during the period from June 2016 to April 2019 with mean follow up two years. It included 20 patients (20 knees) which were undergone for revision TKR due to aseptic loosening of knee prosthesis. These cases were operated at Al-Azhar University hospitals (Al Hussein & Bab El Shaeria). Results: the average knee society score (KSS) was 79 (range from 55 to 94) compared with an average preoperative KSS of 38 (range from 28 to 48). The mean knee function score at the last follow up was 72 (range from 35 to 95) compared with the mean preoperative knee function score of 31 (range from 10 to 55). Conclusions: results of revision TKA due to polyethelene (PE) wear and its resultant osteolysis were mostly satisfactory to the patients

Revision for Aseptic Loosening of Primary Total Knee Arthroplasty

Background: the modes of failure of total knee replacement(TKR) can be classified as intra-articular or extraarticular, as biological or mechanical, as early or late. Aseptic loosening is one of leading cause of failure of total knee replacement. Purpose: it was to spot light on different surgical strategies; to assess the results of 20 cases of revision total knee arthroplasty after aseptic loosening of primary total knee arthroplasty. Materials and Methods: this is a prospective interventional study which was conducted during the period from June 2016 to April 2019 with mean follow up two years. It included 20 patients (20 knees) which were undergone for revision TKR due to aseptic loosening of knee prosthesis. These cases were operated at Al-Azhar University hospitals (Al Hussein & Bab El Shaeria). Results: the average knee society score (KSS) was 79 (range from 55 to 94) compared with an average preoperative KSS of 38 (range from 28 to 48). The mean knee function score at the last follow up was 72 (range from 35 to 95) compared with the mean preoperative knee function score of 31 (range from 10 to 55). Conclusions: results of revision TKA due to polyethelene (PE) wear and its resultant osteolysis were mostly satisfactory to the patients

Effect of polyethylene conformity on total knee arthroplasty early clinical outcomes.

Total knee arthroplasty is a successful procedure in treating subjects with end-stage knee osteoarthritis. The objective of this matched study was to evaluate subjective patient satisfaction and clinical and radiological outcomes in two groups of patients undergoing primary TKA using an identical third-generation design with different conformity in the polyethylene insert. One hundred consecutive patients undergoing TKA because of knee osteoarthritis were randomized in two matched groups. Group A included 50 Posterior-Stabilized (PS) implants, while group B included 50 Medially Congruent (MC) implants. The surgical technique was identical: gap balancing in extension and measured resection in flexion; cruciate ligaments were always removed; the coronal alignment followed the mechanical axis and the tibial slope was set at 3° in the PS group and 5° in the MC. Oxford Knee Score (OKS) and Knee Society Score (KSS) were assessed preoperatively and at 2year minimum follow-up. Two-sample T test statistical analysis was performed. All patients were available at final follow-up: there were no preoperative statistical differences between the two groups in the average preoperative ROM (PS 112°, MC 108°; n.s.), average preoperative KSS (PS 64.4, MC 63.7; n.s.), average preoperative OKS (PS 19.6; MC 19.0; n.s.), and average BMI (PS 34.40, MC 34.60; n.s.). At final follow-up, there were no statistical differences between the two groups in the average OKS (PS 40,5; MC 41.1; n.s.) and in the average KSS (PS 161,5, MC 165,7; n.s.). We found a statistically but not clinically significant difference at final ROM: the average maximum active flexion was 120° in the PS group and 123° in the MC group (s.s.). This study evaluated two biomechanically different polyethylene inserts in the same TKA design, showing that reducing the level of intra-articular conformity had minimal effects on PROMs and objective short-term clinical results but a potentially beneficial effect on ROM. This study suggests that, once a satisfactory intra-operative stability is obtained, the minimal level of constraint should be used. III.

Effectiveness of one-stage total knee arthroplasty with tibial stem extender for knee arthritis complicated with tibial stress fracture

To evaluate the early effectiveness of one-stage total knee arthroplasty (TKA) with tibial stem extender for knee arthritis complicated with tibial stress fractures. Between January 2014 and November 2016, 12 patients (12 knees) with knee arthritis and tibial stress fractures underwent one-stage TKA with tibial stem extender. There were 5 males and 7 females with an average age of 71.5 years (range, 60-77 years). There were 8 cases with osteoarthritis and 4 cases with rheumatoid arthritis. The radiographic examination showed the 6 cases of intra-articular fractures and 6 of extra-articular fractures (including transverse fractures in 4 cases and short oblique fractures in 2 cases); 2 cases complicated with middle and upper fibular stress fractures; all patients of varus deformities. Preoperative Knee Society Score (KSS) clinical score was 31.5±8.4 and functional score was 33.3±9.0. The preoperative range of motion (ROM) of the knee was (65.6±9.6)°. All indexes healed primarily and no wound infection or skin necrosis occurred. All patients were followed up 36.5 months on average (range, 6-52 months). X-ray films showed that all fractures healed at 3-7 months (mean, 4 months); the position of the prosthesis was good, and no loosening or signs of infection occurred. At last follow-up, the KSS clinical score was 90.5±8.9 and functional score was 92.1±7.8; the ROM of the knee was (115.0±9.8)°. All indicators were significantly improved than those before operation ( t=40.340, P= 0.000; t=32.120, P=0.000; t=8.728, P=0.000). One-stage TKA with tibial stem extender for patients with knee arthritis and tibial stress fractures can restore limb alignment, facilitate fracture healing, and obtain the satisfactory early effectiveness.

Increased Patellar Fracture Rate in Total Knee Arthroplasty With Preoperative Varus Greater Than 15°: A Case-Control Study

BackgroundManagement of severe varus deformity requires soft tissue balancing for implantation of low-constraint knee prosthesis. Patellar complications have been rarely studied in this specific group. Our hypothesis was that severe genu varum (>15°) would increase the rate of patellar complications. MethodsUsing a prospective cohort of 4216 prostheses performed at a single center beginning in 1987, we analyzed 280 prostheses having preoperative varus greater than 15°, compared to 673 total knee arthroplasties (TKAs) with a preoperative hip-knee-ankle angle of 180° ± 2°. Preoperative and postoperative clinical and radiological characteristics were compared between the 2 groups, with particular attention paid to patellar complications. ResultsAverage follow-up was 40.2 months (24-239). The mean preoperative Knee Society Score (KSS) was statistically higher in the normal (hip-knee-ankle angle 180° ± 2) axis group (62.65 vs 37.47, P = .001). At the last follow-up, no significant difference was found between the 2 groups in terms of postoperative KSS (87.5 in the varus group vs 87.3 in the normal axis group, P = .87). The rate of satisfied patients was identical between the 2 groups (85.3% vs 88.8%, P = .49). However, at mid-term, there were more patellar fractures in the varus group (2.9% vs 0.9%, P = .005). A significantly lower patellar height in both the varus group and the group of patella fractures (P < .001) was also found. ConclusionTKA in severe varus knees produces a KSS equivalent to TKA in knees with a mechanical axis of 0 ± 2. The risk of patellar fracture could initiate a decline in patella resurfacing in patients with major varus deformation, especially in case of a preoperative patella baja.

Higher failure rate of two-stage revision for infected knee arthroplasties in significantly compromised (host-C) patients.

To evaluate clinical outcomes of two-stage revision arthroplasty for managing infected knee arthroplasties in significantly compromised patients (host-C). This was a prospective consecutive series of two-stage revisions of infected total knee arthroplasties in host-C-type patients with a minimum 2-year follow-up using objective and patient-reported outcome measures. Thirteen consecutive patients were included and prospectively followed with a median 5-year follow-up (range 2-10). Median age was 68years (range 59-73) at time of initial presentation. All patients were type-C host using McPherson classification system. All patients had primary arthroplasties in situ with confirmed chronic infections; the infecting pathogens were Staphylococcus aureus in 5/13 patients, coagulase-negativeStaphylococci in 5/13, and the remaining three patients had mixed growth. All patients underwent two-stage revision protocol. At the final follow-up, 9/13 patients were infection free achieving satisfactory outcomes. Two patients had recurrent infections with different organisms and treated with suppressive antibiotics and salvage knee arthrodesis, respectively. Furthermore, two patients had chronic pain and poor functional outcomes with deficient extensor mechanism and significant bone loss; later underwent salvage knee arthrodesis. The preoperative knee society score (median 35.5; range 22-51; n = 10) showed a statistically significant improvement at the final follow-up (median 79.5; range 49-87; n = 10) p < 0.05. Patients reported outcome scores at the final follow-up were WOMAC-knee (median 59.1; range 47.7-94.7; n = 13) and Oxford knee score (median 26; range 11 to 43; n = 13). This study highlights the challenge of treating infected knee arthroplasties in physiologically compromised patients with 9/13 (69%) having satisfactory clinical outcomes. Case series, level IV.

Short-term effectiveness of total knee arthroplasty assisted by three-dimensional printing osteotomy navigation template

To investigate the short-term effectiveness of total knee arthroplasty (TKA) assisted by three-dimensional (3D) printing osteotomy navigation template. A retrospective study was performed on 60 patients with osteoarthritis bewteen January 2016 and June 2017. Thirty cases underwent TKA assisted by 3D printing osteotomy navigation template (3D printing group) and 30 cases underwent the conventional TKA (conventional TKA group). There was no significant difference in gender, age, body mass index, surgical side, and disease duration between 2 groups ( P>0.05). The operation time, the pre- and post-operative hemoglobin values, the amount of drainage, the Hospital for Special Surgery (HSS) score and Knee Society Score (KSS) of knee joint before operation and at 3 months after operation were observed. And 6 freedom degrees of knee (the varus and valgus angle, the internal and external rotation angle, the antero-posterior displacement, the proximal-distal displacement, the flexion and extension angle, and the internal and external displacement) before operation and at 3 months after operation were recorded by Opti-Knee (the knee 3D motion analysis system). The values of 2 groups were compared with 30 healthy adults (<60 years). The operation time was shorter in 3D printing group than that in conventional TKA group ( t=5.833， P=0.000). The hemoglobin values at 1 and 3 days after operation were higher in 3D printing group than those in conventional TKA group ( P<0.05). The amount of drainage was less in 3D printing group than that in conventional TKA group ( t=5.468， P=0.000). All patients were followed up 6-9 months (mean, 7.3 months). There was no significant difference in pre- and post-operative HSS score and KSS clinical score between 2 groups ( P>0.05). There was no significant difference in preoperative KSS function score between 2 groups ( P>0.05), but the KSS function score of 3D printing group at 3 months after operation was higher than that of conventional TKA group ( P<0.05). Before operation, the varus and valgus angle, the internal and external rotation angle, the antero-posterior displacement, the proximal-distal displacement of 3D printing group and conventional TKA group were larger than that of the healthy adults ( P<0.05); there was no significant difference in the flexion and extension angle and the internal and external displacement between 2 groups and healthy adults ( P>0.05). At 3 months after operation, compared with healthy adults, the varus and valgus angle of conventional TKA group was increased, the flexion and extension angle of conventional TKA group was decreased ( P<0.05); the proximal-distal displacement and the internal and external displacement of 2 groups were decreased ( P<0.05); there was no significant difference in other freedom degrees between groups ( P>0.05). No sign of prosthesis loosening was observed by X-ray examination. Compared with the traditional TKA, TKA assisted by the 3D printing osteotomy navigation template had such advantages as shorter operation time, less postoperative blood loss, and well postoperative recovery.

Midterm Results of Cementless Total Knee Arthroplasty: A Retrospective Case Series.

Background:There is an ongoing debate about whether to use cementless or cemented fixation for Total Knee Arthroplasty (TKA).Objective: The study aimed to assess midterm survivorship of the Vanguard cementless system, and to demonstrate the utility of the Bone Hardness Test (BHT) for the selection of cementless fixation TKA.Methods:From September 2009 through November 2014, 123 total knee arthroplasties were completed, with cementless Vanguard Cruciate Retaining TKA in 110 knees (102 patients) and cemented Vanguard in 13 cases (12 patients). Implant fixation was based on intraoperative assessment of posterior cruciate ligament stability, bone quality, and BHT. All patients with a cementless Vanguard implant were eligible for this retrospective study. Preoperative and postoperative Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index were obtained. Standardized standing anteroposterior and lateral radiographs were taken.Results:Three patients (4 TKAs) were lost to follow-up. The mean follow-up time was 5.5 ± 1.4 years. All scores significantly improved postoperatively. No radiographic failures were observed. Five-year implant survival, with revision of any component for any reason as an endpoint, was 97.2% (95% confidence interval, 91.7 - 99.1%). Five-year survival with revision for aseptic loosening was 100%. Only one knee required revision due to an isolated unrelated bearing exchange, and two additional knees required secondary resurfacing of the patella for retropatellar pain.Conclusion:Good midterm results were obtained with the cementless Vanguard Cruciate Retaining TKA for the treatment of osteoarthritis. The Bone Hardness Test appears to be an effective way to determine the selection of cementless TKA.

Surgical treatment for knee osteoarthritis subsequent to previous femur fractures

Objective To investigate the indications and clinical outcomes of total knee arthroplasty or osteotomy for knee osteoarthritis subsequent to previous femur fractures. Methods Six patients (three male and three female) with knee osteoarthritis subsequent to previous femur fractures were analyzed retrospectively between February 2006 and February 2017. The average age of patients was 58.2±10.3 years old, ranged from 51 to 79 years. Four patients underwent total joint replacement and two underwent osteotomy. The average age of patients in joint replacement group was 60.5±12.3 years old. The age of the two patients in the osteotomy group was 51 and 55 years old, respectively. The extra-articular deformity angle of the coronal plane of the femur, lateral distal femur angle of mechanical axis, hip-knee-ankle angle (HKA) of preoperative and postoperative were determined on long-standing radiography. The mean angle of the extra-articular deformity in the joint replacement group was 17.0±7.7 degrees. The angle of the extra-articular deformity in the osteotomy group was 34 and 20 degrees. Lateral distal femur angle of mechanical axis in the joint replacement group was within the range of 87±7 degrees. Lateral distal femur angle of mechanical axis in the osteotomy group was out of the range of 87±7 degrees. The mean preoperative HKA of the joint replacement group was 161.8±8.0 degrees. The preoperative HKA of the osteotomy group was 155 and 160 degrees, respectively. Knee function was estimated according to knee range of motion and Knee Society Score (KSS). The results of postoperative hip-knee-ankle angle, knee range of motion (ROM) and knee society score were compared between the two groups. Results The mean HKA of the joint replacement group reached 176.0±2.8 degrees at one year postoperatively. The HKA of the osteotomy group improved to 177 and to 175 degrees at one year postoperatively. The average preoperative knee ROM improved significantly from 71±16 degrees preoperatively to 113±5 degrees postoperatively. The mean knee ROM of the joint replacement group was 113.0±6.8 degrees. The knee ROM of two patients in the osteotomy group was 110 and 115 degrees, respectively. The average preoperative KSS score improved significantly from 46±3 preoperatively to 88±3 postoperatively. The mean KSS of the joint replacement group was 88.8±3.0, while the KSS of the osteotomy group was 85 and 82. No bone nonunion was observed in the two patients in osteotomy group. Conclusion For patients with knee osteoarthritis subsequent to previous femur fractures, satisfactory short-term clinical outcomes could be obtained by total knee arthroplasty or osteotomy with the strict selection of proper operative indications. Key words: Femoral fractures; Osteoarthritis; Arthroplasty, replacement, knee

Results of Cemented vs Cementless Primary Total Knee Arthroplasty Using the Same Implant Design

BackgroundAlthough cemented total knee arthroplasty (TKA) continues to be the gold standard, there are patient populations with higher failure rates with cemented TKAs such as the obese, morbidly obese, and younger active males. Cementless TKA usage continues to increase because of the potential benefits of long-term biologic fixation similar to the rise in cementless total hip arthroplasty. The purpose of this study was to evaluate the clinical and radiographic results of cementless TKA using a novel highly porous cementless tibial baseplate. MethodsThis was a retrospective matched case-control study of 400 primary TKAs comparing cementless vs cemented TKAs using the same implant design (Stryker Triathlon; Stryker Inc, Mahwah, NJ). Two-hundred patients with a mean age of 64 years (range 42-88 years) and body mass index (BMI) of 33.9 kg/m2 (range 19.7-57.1 kg/m2) were matched to 200 primary cemented TKA patients with a mean age of 64 years (range 43-87 years) and BMI of 33.1 kg/m2 (range 22.2-53.2 kg/m2). The mean follow-up in the cementless group was 2.4 years (range 2-3.5 years) and in the cemented group was 5.3 years (range 2-10.9 years). Clinical and radiographic analyses were evaluated. Statistical analysis was performed using the Microsoft Excel, version 15.21.1. ResultsThere was no statistical difference in age, BMI, and preoperative Knee Society Scores between the 2 groups (P = .22, P = .82, and P = .43, respectively). Patients in both groups had a similar incidence of postoperative complications (P = .90). Cementless group had 7 revisions with one aseptic loosening of the tibial component (0.5%). Cementless tibial baseplates demonstrated areas of increased bone density at the pegs of the tibial baseplate. The cemented group had 8 total revisions with 5 cases of aseptic loosening (2.5%). ConclusionEarly results of cementless TKA using a highly porous tibial baseplate designed with a keel and 4 pegs appear promising with one case of aseptic loosening at minimum 2-year follow-up. As the demographics of patients undergoing TKA change to include younger, obese, and more active patients, along with increased life expectancy, the use of a highly porous cementless tibial baseplate may be beneficial in providing long-term durable biologic fixation similar to the success of cementless total hip arthroplasty.

Results of Arthroscopic Synovectomy for Treatment of Synovial Lipomatosis (Lipoma Arborescens) of the Knee

Synovial lipomatosis (SL; lipoma arborescens) is a tumor-like condition with villous proliferation of the synovium. The exact etiology of SL is still unknown. The knee is the most commonly involved part. The goal of this retrospective study was to report the results of arthroscopic synovectomy in patients with SL in their knee joints as well as to emphasize the importance of considering this pathology when treating patients with recurrent knee joint effusions. In total, 21 patients (8 females and 13 males) were evaluated retrospectively from May 2009 to July 2014. The mean follow-up period was 29.13 (range, 12-61) months. The mean duration of compliance was 22.76 (range, 7-61) months. All patients were evaluated by Knee Society score pre- and postoperatively. The mean preoperative and last follow-up Knee Society scores were 67.82 and 88.23 points, respectively. There was a significant difference between the preoperative and postoperative Knee Society scores (p = 0.0001). Histopathological examinations showed that the subsynovial layer exhibited diffuse replacement by mature fat cells that had formed villous projections. In addition, infiltration of mononuclear inflammatory cells was observed at different stages. SL is a nondestructive and benign tumor pathology of the knee joint without a clearly identified etiology. The main difficulty in diagnosis is lack of clinical practice.

Single-stage revision for chronic periprosthetic joint infection of the knee: a minimum 4-year follow-up

Background: Periprosthetic joint infection (PJI) is one of the most challenging and frequent complications after hip and knee arthroplasty. This study aimed to determine whether chronic PJI patients who had undergone single-stage knee revision: (I) achieved adequate infection control as assessed by culture of synovial fluid and monitoring of inflammatory markers; (II) regained normal knee function as assessed by the Knee Society Score (KSS). Methods: We retrospectively reviewed 43 patients who had undergone single-stage revision for PJI after total knee arthroplasty (TKA) between April 2005 and October 2011. The most recent follow-up was in October 2014, and the minimum follow-up was 4 years (range, 4–10 years). Results: Participants were 27 men and 16 women with a mean age of 65 years (range, 37–80 years). Infection was controlled by the time of last follow-up in 41 of 43 patients; one patient died for reasons unrelated to infection after completing the 4-year follow-up, one patient had recurrence of PJI that was eradicated by prosthesis removal and second-stage revision, and one patient had a recurrent fungal infection that was controlled by intravenous vancomycin, intra-articular fluconazole, and oral fluconazole. The mean preoperative KSS score was 33.6 (range, 0–61), which had increased significantly by the last follow-up to 63.9 (range, 43–82) points. Conclusions: Single-stage revision for chronic knee PJI achieved a high rate of infection control and acceptable functional outcomes; this is a more convenient alternative that avoids the risks associated with two operations and hospitalizations. Level of Evidence: Level 4, therapeutic study.

Reconstruction of Disrupted Extensor Mechanism After Total Knee Arthroplasty

BackgroundDisruption of the extensor mechanism after total knee arthroplasty (TKA) is a debilitating complication that results in extension lag, limited range of motion, difficulty in walking, frequent falls, and chronic pain. This study presents the clinical and radiographic results of reconstruction after extensor mechanism disruption in TKA patients. MethodsConsecutive patients with allograft reconstruction of extensor mechanism after TKA were identified retrospectively from an academic tertiary center for revision TKA. ResultsSixteen patients with a mean age of 61 ± 14 years at extensor mechanism reconstruction with a minimum of 2-year follow-up were included. The mean follow-up was 3.3 ± 2.2 years. Knee Society score (KSS), before and at final follow-up extension lag, range of motion, and radiographic change in patellar height were reviewed. There were statistically significant improvements between preoperative and final follow-up KSS (P < .001; KSS for pain, preoperative 40 ± 14 points to final follow-up 67 ± 15 points [P < .001]; KSS for function, preoperative 26 ± 21 points to final follow-up 48 ± 25 points [P < .001]). The extension lag was also reduced from 35° ± 16° preoperatively to 14° ± 18° (P < .001) at final follow-up. There was an average proximal patellar migration of 8 ± 10 mm. Five (31%) cases had an extensor lag of >30° or revision surgery for repeat extensor mechanism reconstruction, infection, or arthrodesis. ConclusionOur 10-year experience using allografts during extensor mechanism reconstruction demonstrates reasonable outcomes, but failures are to be anticipated in approximately one-third of patients.

Predictors and Functional Implications of Change in Leg Length After Total Knee Arthroplasty

BackgroundLeg lengthening occurs in 83% of primary total knee arthroplasty (TKA). The effects of leg length discrepancy (LLD) on THA patients are well established. However, patient function and satisfaction associated with LLD after primary TKA has not been analyzed. This study aimed to quantify the magnitude of limb lengthening, identify radiographic and perceived LLD, and correlate these with predictive factors and functional outcomes in a series of TKA patients. MethodsPatients undergoing primary TKA who met inclusion criteria were prospectively enrolled in this study. Leg length measurements were measured on standardized preoperative and postoperative long leg radiographs. Patients completed preoperative and 6-month postoperative Knee Society Score and functional Knee Injury and Osteoarthritis Outcome Score, as well as a postoperative satisfaction and customized leg length–specific functional questionnaire. ResultsNinety-one patients undergoing TKA surgeries were included. Mean overall lengthening was 3.5 mm (range, −31.0 to 21.4 mm; SD, 8.4) with 77% of limbs lengthened; 89% of patients had no LLD (defined as ≥10 mm) after TKA. Postoperative radiographic LLD was associated with increased preoperative LLD (P < .001). Perceived postoperative LLD was associated with female gender (P = .02), decreased satisfaction (18% vs 84%; P < .001), and poorer functional score changes. Perceived LLD was not associated with radiographic LLD. ConclusionRadiographic lengthened LLD is uncommon after primary TKA (11%) and does not correlate with perceived LLD. Patients with perceived LLD have decreased satisfaction and functional score improvements after TKA surgery.

Risk-Benefit on Quality of Life After Total Knee Arthroplasty in Octogenarians

BackgroundClinical outcomes of total knee arthroplasty (TKA) in very older patients have been widely studied, but the available evidence on quality of life (QOL) is limited. The objective was to evaluate the impact of TKA on the QOL in octogenarian patients and assess whether the risk-benefit justified surgery. MethodsProspective study comparing 143 octogenarian and 149 septuagenarian patients. QOL was assessed with the Short Form-12 (SF-12) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaires and functional outcomes with the Knee Society score (KSS). Comorbidity, complications, pain, and satisfaction were also assessed. ResultsMean postoperative follow-up was 3.2 years (range, 2-5 years). Comorbidities, medical complications, transfusion rate, and length stay were not different between groups (P < .05). Comorbidities and complications had no influence on the outcomes. There were no significant differences in preoperative knee KSS, WOMAC, or SF-12 mental scores, but octogenarians had significantly lower functional KSS (P = .003) and SF-12 physical scores (P = .005). At the last follow-up, there were no significant differences in KSS, WOMAC, and SF-12 physical scores (P < .05), but octogenarians had higher SF-12 mental (P = .030) and satisfaction (P = .031) scores. ConclusionTKA provided pain relief, satisfaction, and improvement in QOL for octogenarian patients to the level of the septuagenarian patients. TKA was a suitable option for octogenarian patients with appropriate surgical indications and manageable risk.

Patients at Risk: Large Opioid Prescriptions After Total Knee Arthroplasty

BackgroundOpioids are an effective, and often necessary, treatment of postoperative pain after total knee arthroplasty (TKA). However, it is often difficult to know how much medication patients will need after discharge. The purpose of this study was to determine if patients discharged with greater quantities of opioids after TKA are more likely to request refills. MethodsThis is a retrospective review of 105 primary TKAs performed with at least 1 year of follow-up. Exclusion criteria included bilateral TKA, preoperative opioid use, or reoperation within the first 3 months. Data collected included opioid refills, Knee Society Score, and total and daily morphine equivalent dose (MED) prescribed. ResultsPatients were most commonly discharged on oxycodone (90%), hydromorphone (5%), and hydrocodone/acetaminophen (1%). The average total prescribed MED was 1405 ± 616 mg (range, 273-3250 mg). Patients requiring refills did not differ in the total prescribed MED (1521 ± 624 vs 1349 ± 609 mg; P = .1), daily prescribed MED (153 ± 10 vs 155 ± 7 mg; P = .8), or preoperative Knee Society Score (63 ± 16 vs 60 ± 13; P = .3). Average follow-up time was 2.4 ± 0.5 years. ConclusionThe quantity of opioids prescribed after TKA varied widely, ranging from a total MED of 273-3250 mg. The refill rate did not differ between large prescriptions (≥1400 mg) and smaller prescriptions. Excessive opioid prescriptions should be avoided as they did not decrease the number of refills and pose the risk of divergence and subsequent abuse.

Numbness Around the Total Knee Arthroplasty Surgical Scar: Prevalence and Effect on Functional Outcome

BackgroundNumbness around the surgical scar can be a source of discomfort or dissatisfaction in a proportion of patients undergoing total knee arthroplasty (TKA). Literature reports wide variation in its prevalence and the consequence of numbness on the outcome of TKA is not clear. We investigated the prevalence of numbness, along with contributing factors, and assessed its effect on the functional outcome of TKA. MethodsIn total, 258 knees were included in this prospective patient-reported outcome measure case-control study. Demographic details, type and length of incision, pre-operative and 1-year post-operative Knee Society Scores were recorded and compared. ResultsThe prevalence of numbness at 1 year was 53%, with a female preponderance. Patients older than 70 years were less affected. Discomfort due to numbness was recorded in 8.7% of the patients, 75% of which were female. The length of the incision correlated positively with the presence of numbness. The Knee Society Scores did not correlate with the presence or area of numbness. ConclusionOur findings indicate a high prevalence of numbness after TKA. Nevertheless, numbness does not affect the functional outcome.